What the heck is a spleenwort? There’s an old belief, the doctrine of signatures, that plants whose
shape resembles some part of the human body were meant to be used for medically treating that
part. Nobody is certain when this concept originated, but in the early 1600s a shoemaker from
Görlitz, Germany, one Jacob Böhme, had a vision along the same lines, and wrote a book
about it. Although Böhme made no medically related claims about his beliefs, others interpreted
the idea literally and began treating people.

In the case of spleenwort, the tiny sori (spore packets) on the bottoms of the leaves are shaped like spleens.
”Wort” is an ancient word meaning “plant.” So spleenwort means “plant that has something on it
that looks sort of like a spleen so it must be medicine for spleen problems.”